1. Field of the Invention
The present invention relates, in general, to devices for the temporary repair of leaks in the hulls of ships, and in particular, to a hull hole closure for use with an oil tanker which extends from one side of the tanker to the other, passing under the keel, keeps oil from escaping from the damaged hull, and prevents sea water from passing into the hull and sinking the ship.
2. Information Disclosure Statement
A preliminary patentability search in class 114, subclasses 227, 228, and 229, produced the following patents: Cooper, U.S. Pat. No. 136,817, issued Mar. 18, 1873; Duncan, U.S. Pat. No. 373,133, issued Nov. 15, 1887; Wullyamoz et al., U.S. Pat. No. 1,221,496, issued Apr. 3, 1917; Achiha, U.S. Pat. No. 1,306,938, issued June 17, 1919; U.S. Pat. No. 2,127,871, issued Aug. 23, 1938; Gerardi, U.S Pat. No. 3,400,684, issued Sept. 10, 1968; Buce, U.S. Pat. No. 3,669,055, issued June 13, 1972; Cox, U.S. Pat. No. 4,026,233, issued May 31, 1977; Cloutier, U.S. Pat. No. 4,161,155, issued July 17, 1979; and McDuff et al., U.S. Pat. No. 4,712,502, issued Dec. 15, 1987. While each of the above patents disclose various apparatus for repair of leaks in the hulls of ships, none disclose or suggest the present invention. More specifically, none of the above patents disclose or suggest a hull hole closure, for use with an oil tanker having a hull hole, comprising a flexible, substantially waterproof sheet for covering the hull hole, said sheet for extending under the keel of the tanker from the port side to the starboard side of the tanker, and further comprising inflatable seals on each edge and upper portion of the sheet.
Duncan, U.S. Pat. No. 373,133, Gerardi, U.S. Pat. No. 3,400,684, and Cox, U.S. Pat. No. 4,026,233, describe various hull covers for repairing ship hulls which extend under the keel and around the bow. None of these patents deal with the specific problems of oil tankers, or describe or disclose seals at the edges and upper portion of the hull cover; unlike the present invention, the hull covers of these patents would thus allow oil to escape over the top of the cover in high seas as waves wash oil from the hull. Also, the present invention, having seals at the edges of the hull hole closure, provides a better seal between the sheet and the hull, thus containing the oil within the vessel more completely than would such a cover lacking such seals.
Many prior patents have attempted to solve the problem of covering hull holes by means of localized patches, held in place over the hole by ropes or cables. Cooper, U.S. Pat. No. 136,817, describes an inflatable air-tight bag held in place over the hole by cables extending up to the deck on either side of the ship. Achiha, U.S. Pat. No. 1,306,938, similarly describes an inflatable mat which is held in position over the hull hole by similar cables. The apparatuses of both of these patents, in contrast to the present invention, are difficult to maneuver and position precisely over the hull hole, since they do not extend under the keel of the ship. Also, since they only cover a localized area around the hole, will have a tendency to be pushed upward by the buoyancy of the patch by the water, a problem avoided by the present invention which, having substantially symmetric portions on either side of the keel, would not tend to be dislocated from the hull hole by the force of the surrounding water. Buce, U.S. Pat. No. 3,669,055, describes a compartmentalized patch having an outer cover with compartmentalized passageways that similarly would be difficult to position over the hull hole and which would have a tendency to be pushed out of position by the surrounding seas, once inflated. Similarly, McDuff et al., U.S. Pat. No. 4,712,502, describes a localized patch with inflatable seals around its periphery, held in place by ropes or cables, equally difficult to position and remain over the hull hole.
Wullyamoz et al., U.S. Pat. No. 1,221,496, describes a curtain-like patch of tarred cloth which is unrolled from a roller supported by a pneumatic frame. The present invention has no such frame, and extends under the keel of the ship. Kozloff, U.S. Pat. No. 2,127,871, describes a variety of hull patching devices, including a fabric patch with a plurality of rubber pads on the inner surface. Unlike the present invention, the apparatus of the Kozloff patent does not have inflatable seals on the edges, and is localized, not extending below the keel, thus increasing the difficulty in positioning the patch over the hull hole.
Cloutier, U.S. Pat. No. 4,161,155, describes a frame and wire net used to secure an inflatable bladder and foam layer against the hull, again in a localized patch. The present invention requires no such frame or wire net.